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Author Semenov, A. D.; Hübers, H.-W.; Schubert, J.; Gol'tsman, G. N.; Elantiev, A. I.; Voronov, B. M.; Gershenzon, E. M.
Title Design and performance of the lattice-cooled hot-electron terahertz mixer Type Journal Article
Year 2000 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 88 Issue 11 Pages 6758-6767
Keywords HEB mixer, charge imbalance, HF current distribution
Abstract We present the measurements and the theoreticalmodel of the frequency-dependent noise temperature of a superconductor lattice-cooled hot-electron bolometer mixer in the terahertz frequency range. The increase of the noise temperature with frequency is a cumulative effect of the nonuniform distribution of the high-frequency current in the bolometer and the charge imbalance, which occurs at the edges of the normal domain and at the contacts with normal metal. We show that under optimal operation the fluctuation sensitivity of the mixer is determined by thermodynamic fluctuations of the noise power, whereas at small biases there appears additional noise, which is probably due to the flux flow. We propose the prescription of how to minimize the influence of the current distribution on the mixer performance.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial (up) 306
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Author Hübers, H.-W.; Semenov, A. D.; Richter, H.; Schubert, J.; Hadjiloucas, S.; Bowen, J. W.; Gol'tsman, G.; Voronov, B. M.; Gershenzon, E. M.
Title Antenna pattern of the quasi-optical hot-electron bolometric mixer at terahertz frequencies Type Conference Article
Year 2001 Publication Proc. 12th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 12th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 286-296
Keywords NbN HEB mixers
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication San Diego, CA, USA Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial (up) 323
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Author Il'in, K. S.; Lindgren, M.; Currie, M. A.; Semenov, D.; Gol'tsman, G. N.; Sobolewski, Roman; Cherednichenko, S. I.; Gershenzon, E. M.
Title Picosecond hot-electron energy relaxation in NbN superconducting photodetectors Type Journal Article
Year 2000 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 76 Issue 19 Pages 2752-2754
Keywords NbN HEB detectors, two-temperature model, IF bandwidth
Abstract We report time-resolved characterization of superconducting NbN hot-electron photodetectors using an electro-optic sampling method. Our samples were patterned into micron-size microbridges from 3.5-nm-thick NbN films deposited on sapphire substrates. The devices were illuminated with 100 fs optical pulses, and the photoresponse was measured in the ambient temperature range between 2.15 and 10.6 K (superconducting temperature transition TC). The experimental data agreed very well with the nonequilibrium hot-electron, two-temperature model. The quasiparticle thermalization time was ambient temperature independent and was measured to be 6.5 ps. The inelastic electron–phonon scattering time Ï„e–ph tended to decrease with the temperature increase, although its change remained within the experimental error, while the phonon escape time Ï„es decreased almost by a factor of two when the sample was put in direct contact with superfluid helium. Specifically, Ï„e–ph and Ï„es, fitted by the two-temperature model, were equal to 11.6 and 21 ps at 2.15 K, and 10(±2) and 38 ps at 10.5 K, respectively. The obtained value of Ï„e–ph shows that the maximum intermediate frequency bandwidth of NbN hot-electron phonon-cooled mixers operating at TC can reach 16(+4/–3) GHz if one eliminates the bolometric phonon-heating effect.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial (up) 856
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Author Gershenzon, E. M.; Gershenzon, M. E.; Gol'tsman, G. N.; Semenov, A. D.; Sergeev, A. V.
Title Heating of electrons in a superconductor in the resistive state by electromagnetic radiation Type Journal Article
Year 1984 Publication Sov. Phys. JETP Abbreviated Journal Sov. Phys. JETP
Volume 59 Issue 2 Pages 442-450
Keywords Nb HEB
Abstract The effect of heating of electrons relative to phonons is observed and investigated in a superconducting film that is made resistive by current and by an external magnetic field. The effect is manifested by an increase of the film resistance under the influence of the electromagnetic radiation, and is not selective in the frequency band 10^10-10^15 Hz. The independence of the effect of frequency under conditions of strong scattering by static defects is attributed to the decisive role of electron-electron collisions in the distribution function. The experimentally obtained characteristic time of resistance variation near the superconducting transition corresponds to the relaxation time of the order parameter, while at lower temperatures and fields it corresponds to the time of the inelastic electron-phonon interaction.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ phisix @ Serial (up) 983
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Author Gershenzon, E. M.; Il'in, V. A.; Litvak-Gorskaya, L. B.; Filonovich, S. R.
Title Character of submillimeter photoconductivity in n-lnSb Type Journal Article
Year 1979 Publication Sov. Phys. JETP Abbreviated Journal Sov. Phys. JETP
Volume 49 Issue 1 Pages 121-128
Keywords
Abstract A comprehensive investigation was made of the submillimeter photoconductivity of n -1nSb in the range of wavelengths L = 0.6-8 mm, magnetic fields H = 0-30 kOe, electric fields E = 0.01-0.5 V/cm, and temperatures T = 1.3-30 K. The kinetics of the photoconductivity processes as a function of T, E; and H is investigated. It is shown that impurity photoconductivity does exist for any degree of compensation of extremely purified n-InSb. Particular attention is paid to the hopping photoconductivity realized in strongly compensated n-1nSb (K > 0.8).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ phisix @ Serial (up) 985
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